6 The Philippine Journal of Science 1915 
in the use of the toilet, infected fingers, and eating with the 
hands food taken from a common dish were the channels through 
which the infection chiefly passed from the carrier to another 
person. Public water supplies and articles of food could be 
eliminated as channels of infection, and flies played an entirely 
insignificant part in its spread. 
A considerable proportion of the positive specimens taken 
from dead bodies were from cases in which the cause of death 
was reported as enteritis, diarrhea, dysentery, infantile beri- 
beri, and pulmonary tuberculosis. The codperation given by 
all the physicians of Manila in the detection and isolation of 
cholera was so genuine that it is not believed that there was 
any effort to conceal cases under other diagnoses. Errors in 
diagnosis were made in good faith. Also, it was quite possible 
for persons to die of one disease and still be carriers of an- 
other, or harbor an infection which had not yet time to develop. 
The proportion of cases of pulmonary tuberculosis found pos- 
itive for cholera on examination of the feces is notable. Here 
the tubercular lesions of the intestines in advanced cases ap- 
parently played a considerable part in rendering the alimentary 
tract a more favorable environment for development of cholera 
germs. So also with the other intestinal diseases mentioned. 
Apparently almost any intestinal disorder or interference with 
intestinal digestive function materially predisposes to develop- 
ment of cholera infection if the latter gain access to the ali- 
mentary tract. 
At the outset of the campaign for the detection of cholera 
carriers, the accuracy of the microscopic diagnosis made by the 
Bureav of Science was called into question by various persons, 
who objected that in their opinion true cholera germs could 
not be present as reported, as no carrier was developing the 
disease. To this objection reply was ordinarily made that the 
fact that the persons harboring the cholera germs were carriers 
rather than cases was because they possessed such temporary 
powers of resistance to the germs as to be able to prevent the 
development of the disease. However, it was believed that cases 
of cholera might very well occur in carriers as a result of either 
decrease in vital resistance of the host or increase in virulence 
of the strain of germ being harbored; and very shortly a con- 
siderable number of cases occurred to prove this to be a fact. 
For example, in the search for carriers in Bilibid Prison, con- 
victs 8617, 12765, and 30351 were reported as positive carriers 
on September 10 and 11. They were isolated and examined 
bacteriologically every other day, being found continuously pos- 
